System and means for returning leakage fluid to a main fluid supply



March 23, 1948. D. GREGG 2,438,245

SYSTEM AND IEANS FOR RETURNING LEAKAGE FLUID TO A MAIN FLUID SUPPLY Filed March 21, 1944 Patented Mar. 23, 1948 SYSTEM AND MEANS FOR RETURNING LEAKAGE FLUID TO A MAIN FLUID SUPPLY David Gregg, Caldwell, N. J assignor to Bendix Aviation Corporation, Teterboro, N. J., a corporation of Delaware Application March 21, 1944, Serial No. 527,509

My present invention relates to automatic circulating systems and devices, and move particularly to a novel system and means for returning leakage fluid to a main fluid supply.

An object of my present invention is to provide a novel auxiliary tank for collecting leakage fluid, including means for returning such fluid to the main fluid supply.

Another object of my invention is to provide in a single vessel novel means for collecting leakage fluid, including venturi means for drawing such leakage fluid into the main fluid supply.

Another object of my invention is to provide a novel system for collectin fluid from any device that utilizes fluid pressure to perform work and returning such fluid to the main supply line.

Another object of my invention is to provide a novel compact auxiliary automatic circulating mechanism of great efficiency in comparison to its size and of such simplicity in construction as to adapt it for manufacture and installation at low cost.

The above and further objects and novel features of this invention will more fully appear from the following detailed description and the accompanying drawings wherein like reference characters refer to like parts in the several views. It is to be expressly understood, however, that the drawings are for the purposes of illustration only and are not designed as a definition of the limits of the invention, reference being had for this purpose to the appended claims.

In the drawings:

Figure 1 is a perspective View illustrating my novel auxiliary automatic circulating mechanism and showing in dotted lines the operating parts thereof.

Figure 2 is a sectional view taken along the lines 22 of Figure 3.

Figure 3 is a top plan view of Figure 1.

Figure 4 is a diagrammatic view of my novel system for collecting and returning leakage fluid to a main supply tank.

In the drawings there is shown by numeral i an auxiliary liquid collection tank or chambered vessel having an inlet conduit 2, as shown in Figure 4., leading from a liquid collection sump 3. The'sump 3 is arranged as diagrammatically il- --lustrated in Figure 4 to collect iquid leakage such as oil from a device indicated by numeral i such as an automatic pilot for an aircraft or any othert device utilizing hydraulic pressure to perform work, where there is leakage of such liquid.

A supply conduit 5 leads from a main supply tank 6 to a pump 1 which may be of the gear 4 Claims. (CI. 60-52) type or any other suitable type. A second conduit 8 leads from the pump 1 to the device 4 to be operated by the hydraulic fluid. A by-pass 9 leads from the outlet of the pump 1 to the inlet of the same. The by-pass 9 has one way control valve in of suitable type provided therein and biased in such amanner as to open the by-pass v 9 to the passage of liquid from the outlet to the inlet of the pump l upon the pump pressure exceeding a predetermined value.

An outlet conduit H leads from the device ll to a venturi 52. A second conduit it leads from the outlet of the venturi E2 to the main supply tank ii.

As previously noted the conduit 2 leads from the sump 3 which is arranged in relation to the device t so as to collect any leakage from the device t and conduct such leakage to the auxiliary collection tank i.

The auxiliary liquid collection tank i as best shown in Figures 1, 2 and 3 includes a cup shaped cylinder i having a drainage plug it for removing liquid from the tank i in servicing the same. The tank i has provided a top plate l5 arranged to be fastened to the tank i by bolts l6. Extending'from the top-plate i5 into the tank i is an inlet conduit i1 fixedly mounted in the top plate and extending from a socket [-8 provided in the top plate E5. The socket is has provided suitable screw threads l9 for engagement of the open end of the fluid collection conduit 2. A second opening 20 is provided in the top plate l5 venting the interior of the tank I to atmosphere.

The venturi i2 extends through the tank i from opposite sides thereof and has provided a throat portion 28 opening into which is one end of a suction pipe 22. The opposite ends of the Venturi tube l2 have provided therein suitable screw threads 23 and 24 for engagement of the inlet and outlet conduits ii and i3 respectively.

The opposite end 25 of the suction pipe 22 opens into the cylinder i. The opening of the suction pipe 22 at the end 25 is controlled by a suitable flap valve 26.

Suitable brackets 2i are affixed at the inner surface of the cylinder wall of the tank i stopposite points thereon. The brackets 21 have provided arm portions 28 and 29. Pivotally mounted between the arm portions 28 is a rod member 30 to which there is affixed the flap valve 26. A rod 3! is affixed between the arm portions 29 and has pivotally mounted thereon a suitable float 32. The float 32 has provided actuating fingers 33 and 34 positioned at opposite sides of the flap valve 26 for controlling the position of the flap valve 26. The fingers 33 and 34 are so arranged that upon a predetermined quantity of liquid accumulating in the cylinder i suficlent to cover the open end of the suction pipe 22 the float 32 will actuate the fingers 33 and 35 so as to open the flap valve 25. Liquid flowing through the Venturi throat 2| under pressure of the pump I will create a suction force drawing the liquid accumulated in the tank I upward through the open end 25 of the suction tube 22 and into the throat of the venturi 2| so as to return the liquid to the main supply tank 5.

The flap valve 26 and float 32 are so arranged that the end 25 of the suction tube 22 is not opened by the flap valve 26 until such time as the end 25 is submerged under the level oi the liquid. Thus no air can be drawn into the suction tube 22 by the venturi l2.

From the foregoing it will be readily I have provided a novel arrangement for returning liquid leakage to the main supply line and an arrangement embodying no moving parts, except a valve and a float which operates intermittently without interference to the hydraulic system and a system far simpler and more economical than the conventional electric or'hydraulically operated sump pump.

Moreover, I have provided a novel device which may be readily inserted in any hydraulic system in which there is leakage to be returnedto the main supply tank and a device which utilizes the circulation of oil or other suitable -fluidto provide the desired suction eilect through a venturi or other suitable means for returning the fluid.

Although only one embodiment of the invention has been illustrated and described, various changes in the form and relative arrangement of the parts, which will now appear to those skilled in the art, may be made without departing from the scope of the invention. Reference is, therefore, to be had to the appended claims for a definition of the limits of the invention.

What is claimed is:

1. An automatic circulating system, comprising, in combination, a sounce of fluid, a pressure pump, a device for utilizing said fluid under pressure of said pump, means for collecting fluid leakage from said device, a single conduit for returning fluid from said device under pressure of said pump to said source, Venturi means provided in said single conduit and operated by said return fluid for drawing the leakage fluid irom said collecting means into said return conduit.

2. An automatic circulating system, comprising, in combination, a main liquid supply tank, a pressure pump, a first conduit leading from said supply tank to the inlet 01' said pressure pump, a second conduit leading from the outlet of said pump to a device supplied by said liquid under pressure of said pump, a third conduit for returning said liquid under pressure of said pump to said main supply tank, 'an auxiliary liquid tank, a sump for collecting liquid leakage from said device, a fourth conduit for conducting. said liquid leakage from said sump to said auxiliary liquid tank, a venturi provided in said third liquid return conduit, a suction conduit leading from the throat of said venturi into said auxiliary tank, valve means controlling the opening of said suction conduit to the liquid in said auxiliary tank, and liquid level responsive means provided in said tank for regulating said valve means, whereby upon a predetermined accumulation of liquid in said tank said valve means may be opened for permitting said liquid to be drawn seen that from said tank into said venturi for return to "said main supply tank.

3. An automatic liquid circulating mechanism,

comprising, in combination, a chambered vessel for carrying a liquid medium, a first conduit havins formed therein a venturi in which a suction efiect is created by movement of a liquid medium through said venturi, said conduit extending through opposite sides of said vessel and being supported by said vessel, a second conduit being supported by said vessel and leading into said vessel for conducting a liquid medium thereto, a tube opening from said vessel into the throat of said venturi, whereby the liquid medium carried within said vessel may be drawn into said venturi be intermittently controlled in response to said.

float.

4 A unitary mechanism, comprising, in combination, a tank for carryinga supply of liquid,

said tank having an opening to atmospheric pressure, a first tubular member supportedby.

said tank and extending through the tank, said first tubular member'having a restricted portion forming a Venturi throat positioned within the tank, a second tubular member opening into said restricted portion, said second tubular member afllxed to said first tubular member and extending downwardly in said tank, said second tubular member being open at the lower end thereof, a flap valve device for closing the open end of said second tubular member, a float device for controlling said flap valve device. a bracket aflixed to the inner wall surface of said tank, a first rod carried by said bracket and extending at one side of said 'second tubular member so as to pivotally support said flap valve device, a second rod carried by said bracket and extending parallel to said first rod at the-opposite side of said second tubular member so as to pivotally support said float device, actuating fingers carried by one of said devices and engaging the other of said devices so that said float device may control said flap valve device in accordance with the level of the liquid carried by the tank, and a third tubular member supported by said tank and extending into the tank for supplying liquid thereto. V

' DAVID GREGG.

nnrnnnncns crrnn The following references are of record in the file of this patent:

UNITED STATES PATENTS Great Britain July 19, 1928 

